Sole Structure and Shoe with the Sole Structure

ABSTRACT

A sole structure includes a plate placed between an outsole and a midsole. The plate includes a plate body and first openings. The plate body is made of a material less stretchable than the material of the outsole and is in the form of a thin plate. Each of the first openings extends through a part of the plate body in the vertical direction. The first openings are disposed at a position corresponding to the forefoot and the midfoot on the medial side of a wearer&#39;s foot and is covered by the outsole from below.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2018-178892 filed on Sep. 25, 2018, the entire disclosure of which is incorporated by reference herein.

BACKGROUND

The present disclosure relates to sole structures and shoes with the sole structure.

For example, a sole structure described in Japanese Unexamined Patent Publication No. 2017-035170 is conventionally proposed as a sole structure for shoes which is designed to reduce the burden on a foot of a person wearing a shoe (hereinafter referred to as the “wearer”) during, e.g., running.

Japanese Unexamined Patent Publication No. 2017-035170 discloses a sole structure for shoes which includes an outsole, a midsole made of a soft elastic material and placed on the outsole, and an upper plate placed on the upper surface of the midsole, and a lower plate placed between the outsole and the midsole. Each of the upper plate and the lower plate is made of a material that is more rigid than the material of the midsole and is disposed in a region corresponding to the range from the heel via the midfoot to the forefoot of the wearer's foot.

SUMMARY

In the sole structure of Japanese Unexamined Patent Publication No. 2017-035170, the upper and lower plates restrain excessive bending of the sole structure. This sole structure can thus reduce the burden on metatarsophalangeal joints (MP joints) and a knee joint during running.

However, in the sole structure of Japanese Unexamined Patent Publication No. 2017-035170, the lower plate is placed on the outsole with the entire lower surface of the lower plate being in contact with the upper surface of the outsole. When the wearer's foot strikes the ground or the road surface to move forward during running, especially the part of the outsole which corresponds to the forefoot and midfoot of his/her foot is sandwiched between the ground or the road surface and the lower plate. The outsole therefore tends to wear due to the pressure that is applied to the outsole when the outsole contacts the ground or the road surface. Accordingly, especially the part of the outsole which corresponds to the forefoot and midfoot of the wearer's foot tends to be damaged by aging deterioration.

In the sole structure of Japanese Unexamined Patent Publication No. 2017-035170, the midsole is sandwiched between the upper plate and the lower plate in the vertical direction. Accordingly, the sole structure provides improved rigidity by the upper and lower plates but provides reduced cushioning properties by the midsole especially at the position corresponding to the forefoot and midfoot of the wearer's foot when the wearer's foot strikes the ground or the road surface to move forward.

The present disclosure was developed in view of the above circumferences and it is an object of the present disclosure to make it easier for a wearer to strike the ground or the road surface to move forward during running and to reduce wear of an outsole and provide sufficient cushioning properties of a midsole.

In order to achieve the above object, a first aspect of the present disclosure relates to a sole structure for a shoe. The sole structure includes: an outsole; a midsole made of an elastic material that is less rigid than a material of the outsole and placed on the outsole; and a plate placed between the outsole and the midsole and disposed at a position corresponding to at least a forefoot and a midfoot of a wearer's foot. The plate includes a plate body that is made of a material less stretchable than the material of the outsole and is in the form of a thin plate thinner than the midsole, and at least one first opening extending through a part of the plate body in a vertical direction, and the first opening is disposed at a position corresponding to at least one of the forefoot and the midfoot on a medial side of the wearer's foot and is covered by the outsole from below.

In the first aspect, the plate body placed between the outsole and the midsole restrains excessive bending of the sole structure. At the position corresponding to the forefoot and the midfoot especially on the medial side of the wearer's foot, the stress accumulated in the plate body when the outsole contacts the ground or the road surface is converted to energy for the wearer's foot to strike the ground or the road surface to move forward. It is therefore easier for the wearer to strike the ground or the road surface to move forward during running.

In the first aspect, the at least one first opening extends through a part of the late member in the vertical direction. That is, there is no plate body in the first opening. Moreover, the first opening is covered by the outsole from below. The plate body is thus configured so that not the entire lower surface of the plate body contacts the upper surface of the outsole. Accordingly, even though the outsole is sandwiched between the ground or the road surface and the plate body when the wearer's foot strikes the ground or the road surface to move forward during running, the pressure that is applied to the outsole when the outsole contacts the ground or the road surface tends to escape from the outsole toward the midsole through the first opening. Wear of the outsole is therefore reduced at the position where the outsole particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward, namely at the position corresponding to the forefoot and the midfoot on the medial side of the wearer's foot. Accordingly, damage to the outsole is less likely to be caused by aging deterioration.

The plate body is made of a material less stretchable than the material of the outsole and is in the form of a thin plate thinner than the midsole. The cushioning properties of the midsole are therefore less likely to be reduced at the position corresponding to the forefoot and the midfoot of the wearer's foot. Since there is no plate body in the first opening, the sole structure tends to provide sufficient cushioning properties of the midsole at the position of the first opening.

Accordingly, the sole structure of the first aspect makes it easier for the wearer to strike the ground or the road surface to move forward, reduces wear of the outsole, and provides sufficient cushioning properties of the midsole.

According to a second aspect of the present disclosure, in the first aspect, the first opening is longer in a longitudinal direction of the sole structure than in a lateral direction of the sole structure.

In the second aspect, the first opening is longer in the longitudinal direction of the sole structure than in the lateral direction of the sole structure. Flexural rigidity of the plate body in the longitudinal direction of the sole structure is therefore relatively increased. Accordingly, excessive bending of the sole structure in the longitudinal direction of the sole structure is restrained, and it becomes easier for the wearer to strike the ground or the road surface to move forward during running.

According to a third aspect of the present disclosure, in the first aspect, the plate has a plurality of the first openings, and the plurality of first openings are disposed at a position corresponding to the forefoot and the midfoot on the medial side of the wearer's foot.

In the third aspect, the plurality of first openings are disposed at the position corresponding to the forefoot and the midfoot on the medial side of the wearer's foot. Wear of the outsole is therefore further reduced and the cushioning properties of the midsole are improved at the position where the outsole particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward.

According to a fourth aspect of the present disclosure, in the first aspect, the plate further has at least one second opening extending through a part of the plate body in the vertical direction, and the second opening is disposed at a position corresponding to the midfoot on a lateral side of the wearer's foot and is covered by the outsole from below.

In the fourth aspect, since the plate has the second opening, the lower surface of the plate body does not contact the upper surface of the outsole also at the position corresponding to the midfoot on the lateral side of the wearer's foot. With this configuration, when the wearer's foot strikes the ground or the road surface to move forward, the pressure that is applied to the outsole when the outsole contacts the ground or the road surface tends to escape from the outsole toward the midsole through the second opening. Wear of the outsole is therefore reduced and sufficient cushioning properties of the midsole are provided also at the position corresponding to the midfoot on the lateral side of the wearer's foot.

According to a fifth aspect of the present disclosure, in the fourth aspect, the second opening is longer in the longitudinal direction of the sole structure than in the lateral direction of the sole structure.

In the fifth aspect, the second opening is longer in the longitudinal direction of the sole structure than in the lateral direction of the sole structure. Flexural rigidity of the plate body in the longitudinal direction of the sole structure is therefore relatively increased. Accordingly, excessive bending of the sole structure in the longitudinal direction of the sole structure is restrained, and it becomes easier for the wearer to strike the ground or the road surface to move forward during running.

According to a sixth aspect of the present disclosure, in the first aspect, the plate further has at least one third opening extending through a part of the plate body in the vertical direction, the third opening is disposed so as to correspond to a position including the forefoot on the lateral side of the wearer's foot and is covered by the outsole from below, and the first opening has a larger opening area than the third opening area.

In the sixth aspect, since the plate has the third opening, wear of the outsole is restrained and sufficient cushioning properties of the midsole are provided also at the position corresponding to the forefoot on the lateral side of the wearer's foot. Moreover, the first opening has a larger opening area than the third opening. Accordingly, wear of the outsole is further restrained and the cushioning properties of the midsole are relatively improved at the position where the outsole particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward, namely at the position corresponding to the forefoot and the midfoot on the medial side of the wearer's foot.

According to a seventh aspect of the present disclosure, in the fourth aspect, the plate further has at least one third opening extending through a part of the plate body in the vertical direction, the third opening is disposed so as to correspond to a position including the forefoot on the lateral side of the wearer's foot and is covered by the outsole from below, and the second opening has a larger opening area than the third opening area.

In the seventh aspect, since the plate has the third opening, wear of the outsole is restrained and sufficient cushioning properties of the midsole are provided also at the position corresponding to the forefoot on the lateral side of the wearer's foot. Moreover, the second opening has a larger opening area than the third opening. Accordingly, wear of the outsole is further restrained and the cushioning properties of the midsole are relatively improved at the position corresponding to the midfoot on the lateral side of the wearer's foot.

An eighth aspect of the present disclosure is a shoe including the sole structure of any one of the first to seventh aspects.

The eighth aspect provides the shoe has functions and effects similar to those of any one of the first to seventh aspects.

As described above, the sole structure or the shoe with the sole structure according to the present disclosure makes it easier for the wearer to strike the ground or the road surface to move forward, reduces wear of the outsole, and provides sufficient cushioning properties of the midsole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a sole structure according to an embodiment;

FIG. 2 is a bottom view of the sole structure according to the embodiment;

FIG. 3 is a side view of the sole structure according to the embodiment as viewed from the lateral side;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 1;

FIG. 5 is a sectional view taken along line V-V in FIG. 1;

FIG. 6 is a sectional view taken along line VI-VI in FIG. 1;

FIG. 7 is a sectional view taken along line VII-VII in FIG. 1;

FIG. 8 is a view corresponding to FIG. 1, illustrating in phantom the skeletal structure of a wearer's foot shown superimposed on a plate of the sole structure according to the embodiment;

FIG. 9 is a plan view illustrating the configuration of a plate in a first modification; and

FIG. 10 is a plan view illustrating the configuration of a plate in a second modification.

DETAILED DESCRIPTION

An embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the embodiment is merely illustrative in nature and is not intended to limit the invention, its application or uses.

FIG. 1 generally shows a sole structure 1 according to an embodiment of the present disclosure. Shoes with this sole structure 1 are used as, e.g., running shoes or sports shoes for various sports.

Only the sole structure 1 for left shoes is illustrated herein. A sole structure 1 for right shoes is configured symmetrically with the sole structure 1 for left shoes. Accordingly, in the following description, only the sole structure 1 for left shoes will be described, and description of the sole structure 1 for right shoes will be omitted.

In the following description, the terms “upper (upper side)” and “lower (lower side)” indicate relative positions in the vertical direction of the sole structure 1, and the terms “front (front side)” and “rear (rear side)” indicate relative positions in the longitudinal direction of the sole structure 1. The “medial side” and the “lateral side” indicate relative positions in the lateral direction of the sole structure 1. In FIGS. 1 and 8, F represents the position corresponding to the forefoot of a foot of a person wearing a shoe with the sole structure 1 (hereinafter referred to as the “wearer”), M represents the position corresponding to the midfoot of the wearer's foot, and H represents the position corresponding to the hindfoot of the wearer's foot.

Outsole

As shown in FIGS. 1 to 3, the sole structure 1 includes an outsole 2. The outsole 2 is disposed in a region corresponding to the range from the forefoot F to the hindfoot H of the wearer's foot.

The outsole 2 is made of a hard elastic material that is harder than the material of a midsole 3 described later. Specific examples of the material suitable for the outsole 2 include thermoplastic resins such as ethylene-vinyl acetate copolymer (EVA), thermosetting resins such as polyurethane (PU), and rubber materials such as butadiene rubber and chloroprene rubber.

It is preferable that the hardness of the outsole 2 be, e.g., 50A to 80A (more preferably 60A to 70A) on the Asker A scale.

Midsole

As shown in FIGS. 1 to 3, the sole structure 1 includes the midsole 3. The midsole 3 is configured to support the sole of the wearer's foot. The midsole 3 is placed on the outsole 2 via, e.g., an adhesive. The upper surface of the midsole 3 is configured as a sole support surface 3 a that supports the sole of the wearer's foot. The shoe with the sole structure 1 includes an upper (not shown) that covers the wearer's foot. The upper is provided along the peripheral edge of the midsole.

The midsole 3 is made of a soft elastic material that is less rigid than the material of the outsole 2. Specific examples of the material suitable for the midsole 3 include thermoplastic synthetic resins such as ethylene-vinyl acetate copolymer (EVA) and their foams, thermosetting resins such as polyurethane (PU) and their foams, and rubber materials such as butadiene rubber and chloroprene rubber and their foams.

It is preferable that the hardness of the midsole 3 be, e.g., 15C to 65C (specifically 55C) on the Asker C scale.

As also shown in FIGS. 4 and 7, the midsole 3 has an accommodating portion 3 b that accommodates a cushioning body 20 described later. The accommodating portion 3 b is formed in a region corresponding to the range from the midfoot M to the hindfoot H of the wearer's foot. The accommodating portion 3 b is recessed downward from the sole support surface 3 a of the midsole 3.

Plate

As shown in FIG. 1, the sole structure 1 includes a plate 4. The plate 4 is disposed at a position corresponding to at least the forefoot F and the midfoot M of the wearer's foot. Specifically, the plate 4 of the present embodiment is disposed in a region corresponding to the range from the forefoot F to the hindfoot H of the wearer's foot. As shown in FIGS. 3 to 7, the plate 4 is placed between the outsole 2 and the midsole 3.

As shown in FIGS. 1 to 8, the plate 4 has a plate body 5.

The plate body 5 is made of a material that is less stretchable than the material of the outsole 2. Specifically, the plate body 5 is preferably made of a material that is more rigid than the material of the outsole 2. This configuration further restrains excessive bending of the sole structure 1 and allows the wearer's foot to more quickly strike the ground or the road surface to move forward during running.

Examples of the material suitable for the plate body 5 include resin materials or rubber materials which are harder than the material of the outsole 2 and tape materials made of fabric. The plate body 5 made of a resin material with high hardness is illustrated in the present embodiment.

It is preferable that the hardness of the plate 4 be, e.g., 40D to 80D (specifically 70D) on the Shore D hardness scale.

As shown in FIGS. 3 to 7, the plate body 5 is in the form of a thin plate thinner than the midsole 3. It is preferable that the plate body 5 be in the form of a thin plate thinner than the maximum thickness of the outsole 2. Specifically, it is preferable that the plate body 5 have a thickness of, e.g., 0.5 to 2.0 mm. More specifically, it is preferable that the plate body 5 have a thickness of, e.g., 1.5 mm.

In FIGS. 3 and 4, a neutral axis A is shown by an imaginary line (long dashed short dashed line) extending in the longitudinal direction of the sole structure 1. The neutral axis A corresponds to the axis of the sole structure 1 at the time the sole structure 1 is bent and deformed so as to be curved downward as viewed from the side. When the sole structure 1 is bent and deformed, the deformation of the part of the sole structure 1 which is located below the neutral axis A is relatively larger than that of the part of the sole structure 1 which is located above the neutral axis A. The plate body 5, which is made of a material more rigid than the material of the outsole 2, is placed on the outsole 2 at a position below the neutral axis A. The plate body 5 restrain deformation of the part of the sole structure 1 which is located below the neutral axis A. Excessive bending of the sole structure 1 is thus restrained as a whole.

The rear part of the plate body 5 branches into two portions on the medial and lateral sides. Namely, the plate body 5 has a medial-side branch portion 6 and a lateral-side branch portion 7. The medial-side branch portion 6 and the lateral-side branch portion 7 are disposed in a region corresponding to the range from the midfoot M to the hindfoot H of the wearer's foot.

As shown in FIGS. 1 and 8, the plate body 5 includes protruding portions 8. Each protruding portion 8 is disposed at a position corresponding to the midfoot M of the wearer's foot. The protruding portions 8 extend in the longitudinal direction of the sole structure 1. As shown in FIGS. 6 and 7, the protruding portions 8 protrude upward from the peripheral edges on the medial and lateral sides of the plate body 5. The protruding portions 8 improve rigidity of the plate body 5 at a position corresponding to the midfoot M of the wearer's foot, so that the sole structure 1 can more stably support the wearer's foot.

First Opening

As shown in FIGS. 1 and 2, the plate 4 has at least one first opening 11. In the present embodiment, the plate 4 has a plurality of (in the illustrated example, three) first openings 11.

Each of the first openings 11 extends through a part of the plate body 5 in the vertical direction. The first openings 11 are longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1. The first openings 11 have a larger opening area than third openings 13 described later.

As shown in FIGS. 2 and 4 to 6, the first openings 11 are covered by the outsole 2 from below. A part of the lower part of the midsole 3 is embedded in each of the first openings 11. At each of the positions of the first openings 11, the part of the lower part of the midsole 3 which is embedded in the first opening 11 is in close contact with a part of the upper surface of the outsole 2. With this configuration, the pressure that is applied to the outsole 2 when the outsole 2 contacts the ground or the road surface tends to escape from the outsole 2 toward the midsole 3 through the first openings 11.

The first openings 11 are formed at intervals in the longitudinal direction of the sole structure 1. As also shown in FIG. 8, the first openings 11 are disposed at a position corresponding to the forefoot F and the midfoot M on the medial side of the wearer's foot.

The first opening 11 closest to the front side of the plate body 5 is disposed so as to correspond to, e.g., a position surrounded by the first distal phalanx DP1, the first proximal phalanx PP1, the second middle phalanx IP2, and the second proximal phalanx PP2 of the wearer's foot.

The second closest first opening 11 to the front side of the plate body 5 is disposed so as to correspond to, e.g., a position including the proximal head of the first proximal phalanx PP1 and the distal head of the first metatarsal bone MT1 near the metatarsophalangeal joint MP of the wearer's foot.

The third closest first opening 11 to the front side of the plate body 5 is disposed so as to correspond to, e.g., a position between the first metatarsal bone MT1 and the second metatarsal bone MT2 in the midfoot M of the wearer's foot.

Second Opening

As shown in FIGS. 1 and 2, the plate 4 has at least one second opening 12. In the present embodiment, the plate 4 has a single second opening 12.

The second opening 12 extends through a part of the plate body 5 in the vertical direction. The second opening 12 is longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1. The second opening 12 has a larger opening area than the third openings 13 described later.

As shown in FIGS. 2 and 6, the second opening 12 is covered by the outsole 2 from below. A part of the lower part of the midsole 3 is embedded in the second opening 12. At the position of the second opening 12, the part of the lower part of the midsole 3 which is embedded in the second opening 12 is in close contact with a part of the upper surface of the outsole 2. With this configuration, the pressure that is applied to the outsole 2 when the outsole 2 contacts the ground or the road surface tends to escape from the outsole 2 toward the midsole 3 through the second opening 12.

As also shown in FIG. 8, the second opening 12 is disposed at a position mainly corresponding to the midfoot M on the lateral side of the wearer's foot. Specifically, the second opening 12 is disposed so as to correspond to, e.g., a position between the third metatarsal bone MT3 and the fourth metatarsal bone MT4 behind the metatarsophalangeal joints MP of the wearer's foot.

Third Opening

The plate 4 has at least one third opening 13. In the present embodiment, the plate 4 has a plurality of (in the illustrated example, three) third openings 13.

Each of the third openings 13 extends through a part of the plate body 5 in the vertical direction. The third openings 13 are longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1.

As shown in FIGS. 2 and 5, the third openings 13 are covered by the outsole 2 from below. A part of the lower part of the midsole 3 is embedded in each of the third openings 13. At each of the positions of the third openings 13, the part of the lower part of the midsole 3 which is embedded in the third opening 13 is in close contact with a part of the upper surface of the outsole 2. With this configuration, the pressure that is applied to the outsole 2 when the outsole 2 contacts the ground or the road surface tends to escape from the outsole 2 toward the midsole 3 through the third openings 13.

The third openings 13 are formed at intervals in the longitudinal and lateral directions of the sole structure 1. As also shown in FIG. 8, the third openings 13 are disposed so as to correspond to a position including the forefoot F on the lateral side of the wearer's foot.

The third opening 13 located on the front side of the plate body 5 is disposed so as to correspond to, e.g., a position including the third middle phalanx IP3 and the third proximal phalanx PP3 of the wearer's foot.

The third opening 13 located close to the middle of the plate body 5 is disposed so as to correspond to, e.g., a position between the second proximal phalanx PP2 and the third proximal phalanx PP3 of the wearer's foot.

The third opening 13 located on the lateral side of the plate body 5 is disposed so as to correspond to, e.g., a position between the fourth proximal phalanx PP4 and the fifth proximal phalanx PP5 of the wearer's foot.

Cushioning Body

As shown in FIGS. 1 and 3, the sole structure 1 includes the cushioning body 20. The cushioning body 20 is capable of absorbing a vertical impact on its upper surface. With this configuration, the cushioning body 20 reduces the vertical impact especially on the heel (the calcaneus HL shown in FIG. 8) of the wearer's foot when the outsole 2 contacts the ground or the road surface.

Examples of the material suitable for the cushioning body 20 include thermoplastic synthetic resins such as ethylene-vinyl acetate copolymer (EVA) and their foams, thermosetting resins such as polyurethane (PU) and their foams, and rubber materials such as butadiene rubber and chloroprene rubber and their foams. The cushioning body 20 is preferably made of a soft elastic material that is less rigid than the material of the midsole 3. Specifically, it is preferable that the hardness of the cushioning body 20 be, e.g., 40C on the Asker C scale.

The cushioning body 20 is disposed at a position corresponding to the midfoot M and the hindfoot H of the wearer's foot. Specifically, the cushioning body 20 is formed integrally with the midsole 3 via an adhesive etc. with the cushioning body 20 accommodated in the accommodating portion 3 b. The cushioning body 20 may be molded integrally with the midsole 3 with the cushioning body 20 accommodated in the accommodating portion 3 b.

As shown in FIGS. 4 and 7, the cushioning body 20 has tilted portions 22. The tilted portion 22 located at a front end 21 of the cushioning body 20 is formed so that the front end 21 is tilted downward toward the rear (see FIG. 4). In the present embodiment, the tilted portions 22 are continuous with each other along the entire length of the lower corner of the cushioning body 20.

As shown in FIG. 1, the cushioning body 20 and the plate body 5 overlap each other in the vertical direction at a position corresponding to the midfoot M of the wearer's foot.

Specifically, as shown in FIG. 4, the front end 21 of the cushioning body 20 is located at a position corresponding to the midfoot M of the wearer's foot. At least a part of the front end 21 of the cushioning body 20 overlaps a part of the plate body 5 in the vertical direction.

As shown in FIG. 7, a part on the medial side of the cushioning body 20 overlaps the medial-side branch portion 6 of the plate body 5 in the vertical direction. Moreover, a part on the lateral side of the cushioning body 20 overlaps the lateral-side branch portion 7 of the plate body 5 in the vertical direction.

Functions and Effects of Embodiment

As described above, in the sole structure 1 according to the embodiment, the plate body 5 disposed between the outsole 2 and the midsole 3 restrains excessive bending of the sole structure 1. At the position corresponding to the forefoot F and the midfoot M especially on the medial side of the wearer's foot, the stress accumulated in the plate body 5 when the outsole 2 contacts the ground or the road surface is converted to energy for the wearer's foot to strike the ground or the road surface to move forward. It is therefore easier for the wearer to strike the ground or the road surface to move forward during running.

Each of the first openings 11 extends through a part of the plate body 5 in the vertical direction. That is, there is no plate body 5 in the first openings 11. The first openings 11 are covered by the outsole 2 from below. The plate body 5 is thus configured so that not the entire lower surface of the plate body 5 contacts the upper surface of the outsole 2. Accordingly, even though the outsole 2 is sandwiched between the ground or the road surface and the plate body 5 when the wearer's foot strikes the ground or the road surface to move forward during running, the pressure that is applied to the outsole 2 when the outsole 2 contacts the ground or the road surface tends to escape from the outsole 2 toward the midsole 3 through the first openings 11. Wear of the outsole 2 is therefore reduced at the position where the outsole 2 particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward, namely at the position corresponding to the forefoot F and the midfoot M on the medial side of the wearer's foot. Accordingly, damage to the outsole 2 is less likely to be caused by aging deterioration.

The plate body 5 is made of a material less stretchable than the material of the outsole 2 and is in the form of a thin plate thinner than the midsole 3. The cushioning properties of the midsole 3 are therefore less likely to be reduced at the position corresponding to the forefoot F and the midfoot M of the wearer's foot. Since there is no plate body 5 in the first openings 11, the sole structure 1 tends to provide sufficient cushioning properties of the midsole 3 at the positions of the first openings 11.

The sole structure 1 according to the embodiment makes it easier for the wearer foot to strike the ground or the road surface to move forward, reduces wear of the outsole 2, and provides sufficient cushioning properties of the midsole 3.

The first openings 11 are longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1. Flexural rigidity of the plate body 5 in the longitudinal direction of the sole structure 1 is therefore relatively increased. Accordingly, excessive bending of the sole structure 1 in the longitudinal direction of the sole structure 1 is restrained, and it becomes easier for the wearer to strike the ground or the road surface to move forward during running.

The first openings 11 are disposed at the position corresponding to the forefoot F and the midfoot M on the medial side of the wearer's foot. Wear of the outsole 2 is therefore further reduced and the cushioning properties of the midsole 3 are improved at the position where the outsole 2 particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward.

The plate 4 has the second opening 12 extending through a part of the plate body 5 in the vertical direction. The second opening 12 is disposed at the position corresponding to the midfoot M on the lateral side of the wearer's foot and is covered by the outsole 2 from below. Since the plate 4 has the second opening 12, the lower surface of the plate body 5 does not contact the upper surface of the outsole 2 also at the position corresponding to the midfoot M on the lateral side of the wearer's foot. Accordingly, when the wearer's foot strikes the ground or the road surface to move forward, the pressure that is applied to the outsole 2 when the outsole 2 contacts the ground or the road surface tends to escape from the outsole 2 toward the midsole 3 through the second opening 12. Wear of the outsole 2 is therefore reduced and sufficient cushioning properties of the midsole 3 are provided also at the position corresponding to the midfoot M on the lateral side of the wearer's foot.

The second opening 12 is longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1. Flexural rigidity of the plate body 5 in the longitudinal direction of the sole structure 1 is therefore relatively increased. Accordingly, excessive bending of the sole structure 1 in the longitudinal direction of the sole structure 1 is restrained, and it becomes easier for the wearer to strike the ground or the road surface to move forward during running.

Since the plate 4 has the third openings 13, wear of the outsole 2 is restrained and sufficient cushioning properties of the midsole 3 are provided also at the position corresponding to the forefoot F on the lateral side of the wearer's foot.

The first openings 11 have a larger opening area than the third openings 13. Accordingly, wear of the outsole 2 is further restrained and the cushioning properties of the midsole 3 are relatively improved at the position where the outsole 2 particularly tends to contact the ground or the road surface when the wearer's foot strikes the ground or the road surface to move forward, namely at the position corresponding to the forefoot F and the midfoot M on the medial side of the wearer's foot.

The second opening 12 has a larger opening area than the third openings 13. Accordingly, wear of the outsole 2 is further restrained and the cushioning properties of the midsole 3 are relatively improved at the position corresponding to the midfoot M on the lateral side of the wearer's foot.

A shoe having the sole structure 1 according to the embodiment also has the above functions and effects.

First Modification of Embodiment

In the above embodiment, the plate 4 has the plurality of first openings 11. However, the present disclosure is not limited to this form. For example, as in a first modification shown in FIG. 9, the plate 4 may have only one first opening 11. Specifically, the first opening 11 in the first modification is disposed in a region corresponding to the range from the forefoot F to the midfoot M on the medial side of the wearer's foot.

In the above embodiment, the plate 4 has the second opening 12 and the third openings 13. However, the present disclosure is not limited to this form. As in the first modification shown in FIG. 9, the plate 4 may not have the second opening 12 and the third openings 13.

Second Modification of Embodiment

In the above embodiment, the first openings 11 are longer in the longitudinal direction of the sole structure 1 than in the lateral direction of the sole structure 1. However, the present disclosure is not limited to this form. For example, as in a second modification shown in FIG. 10, the first openings 11 may have a substantially circular shape so as to have substantially the same length in both the longitudinal and lateral directions of the sole structure 1.

In the second modification, the first openings 11 have substantially the same opening area as the third openings 13. Similarly, the second opening 12 has substantially the same opening area as the third openings 13.

Other Embodiments

In the above embodiment, the plate 4 is disposed in the region corresponding to the range from the forefoot F to the hindfoot H of the wearer's foot. However, the present disclosure is not limited to this form. The plate 4 need only be disposed at a position corresponding to at least the forefoot F and the midfoot M of the wearer's foot.

In the above embodiment, the protruding portions 8 are formed along the peripheral edges on the medial and lateral sides of the plate body 5. However, the present disclosure is not limited to this form. For example, at least one protruding portion 8 may be formed along the peripheral edge on either the medial side or the lateral side of the plate body 5. Alternatively, the protruding portions 8 may not be formed along the peripheral edges on the medial and lateral sides of the plate body 5.

In the above embodiment, the cushioning body 20 has the tilted portions 22. However, the present disclosure is not limited to this form. For example, the front end 21 of the cushioning body 20 may have such a stepped shape that the front end 21 is gradually withdrawn rearward as it gets closer to the bottom of the cushioning body 20. In this form, at the position corresponding to the midfoot M of the wearer's foot, the cushioning properties gradually decrease as the contact part of the outsole 2 with the ground or the road surface is shifted forward. Accordingly, when the outsole 2 contacts the ground or the road surface, the cushioning properties provided by the cushioning body 20 are gradually reduced so as not to give the wearer an uncomfortable feel in his/her foot, and the wearer can transition to striking the ground or the road surface to move forward while experiencing such gradually reduced cushioning properties.

Although the embodiments of the present disclosure are described above, the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

The present disclosure is industrially applicable as a sole structure for, e.g., running shoes and shoes for various sports and shoes with the sole structure. 

What is claimed is:
 1. A sole structure for a shoe, comprising: an outsole; a midsole made of an elastic material that is less rigid than a material of the outsole and placed on the outsole; and a plate placed between the outsole and the midsole and disposed at a position corresponding to at least a forefoot and a midfoot of a wearer's foot, wherein the plate includes a plate body that is made of a material less stretchable than the material of the outsole and is in the form of a thin plate thinner than the midsole, and at least one first opening extending through a part of the plate body in a vertical direction, and the first opening is disposed at a position corresponding to at least one of the forefoot and the midfoot on a medial side of the wearer's foot and is covered by the outsole from below.
 2. The sole structure of claim 1, wherein the first opening is longer in a longitudinal direction of the sole structure than in a lateral direction of the sole structure.
 3. The sole structure of claim 1, wherein the plate has a plurality of the first openings, and the plurality of first openings are disposed at a position corresponding to the forefoot and the midfoot on the medial side of the wearer's foot.
 4. The sole structure of claim 1, wherein the plate further has at least one second opening extending through a part of the plate body in the vertical direction, and the second opening is disposed at a position corresponding to the midfoot on a lateral side of the wearer's foot and is covered by the outsole from below.
 5. The sole structure of claim 4, wherein the second opening is longer in the longitudinal direction of the sole structure than in the lateral direction of the sole structure.
 6. The sole structure of claim 1, wherein the plate further has at least one third opening extending through a part of the plate body in the vertical direction, the third opening is disposed so as to correspond to a position including the forefoot on the lateral side of the wearer's foot and is covered by the outsole from below, and the first opening has a larger opening area than the third opening area.
 7. The sole structure of claim 4, wherein the plate further has at least one third opening extending through a part of the plate body in the vertical direction, the third opening is disposed so as to correspond to a position including the forefoot on the lateral side of the wearer's foot and is covered by the outsole from below, and the second opening has a larger opening area than the third opening area.
 8. A shoe comprising the sole structure of claim
 1. 9. A shoe comprising the sole structure of claim
 2. 10. A shoe comprising the sole structure of claim
 3. 11. A shoe comprising the sole structure of claim
 4. 12. A shoe comprising the sole structure of claim
 5. 13. A shoe comprising the sole structure of claim
 6. 14. A shoe comprising the sole structure of claim
 7. 